Oddbean new post about | logout
 Some progress on the #AppleLisaClone today.

-Received a new COP402 processor to replace the COP402M (microchannel version).

-Replaced the two new W65C22N with real MOS 6522 chips (from a 1541 floppy drive!)

-Replaced a 74HC132 with a proper 74LS132 (IO board clock).

With that, soft power now works the way it should!

Next problem: it gives a single beep at startup with a scrambled screen (see video). Fault: CPU or RAM?

#RetroComputing

https://files.mastodon.social/media_attachments/files/111/071/203/645/400/593/original/11fd5526fd3828e9.mp4